1. Technical Field
The invention relates to a wiring pattern forming method, and a semiconductor device provided with a wiring pattern manufactured by using a circuit wiring forming method, an electro-optical device, and electronic equipment, and a film pattern forming method.
2. Related Art
The semiconductor device is formed such that circuit wiring on which a thin film (hereinafter referred to as the “wiring film”) made up of a conductor is arranged is layered over a thin film such as an insulation film covering the circuit wiring. For an efficient forming method of circuit wiring and a thin film, there is known a so-called inkjet method in which a functional liquid including a thin film material such as disclosed in JP-A-11-274671 as a solute is ejected from a liquid droplet ejection head, and the impacted functional liquid is dried to form the circuit wiring and the thin film excepting a solvent.
In the inkjet method, the circuit wiring has a bank arranged on a substrate, forming a concavity surrounded by the bank which is as flat-shaped as the circuit wiring, whereby the functional liquid is spewed out, so that by drying the functional liquid, which was spewed out and impacted on the concavity, and forming a wiring film, any shape is formed.
Further, in a device such as a semiconductor device which is formed as the circuit wiring and the thin film are layered over, resulting from a step between the circuit wiring and its periphery, a defect may occur on the thin film layered over the circuit wiring. To prevent the defect, there is proposed a method of leveling the step between the circuit wiring and the periphery as described in JP-A-2-132831.
JP-A-11-274671 is a first example of related art. JP-A-2-132831 is a second example of related art.
However, as shown in FIG. 19A, it is desirable for a liquid droplet 501, which was spewed out so as to impact a concavity 534, to enter the concavity 534 like a functional liquid 502 shown in FIG. 19B. Yet, like a functional liquid 503 shown in FIG. 19B, part thereof may be deposited on an upper surface of a bank B.
As shown in FIG. 19C, when forming a wiring film 504 through drying the functional liquid 502, the functional liquid 503 is also dried, whereby there may be formed a bulge 506, as the functional liquid 503 is dried to cause the wiring film 504 to be bulged out onto a cornered portion of the bank B, and a residue 507 of a wiring material of a solute of the functional liquid 503 may remain on the bank B.
Further, when the insulation film 510 covering the wiring film 504 is formed on the wiring film 504 and the bank B, as shown in FIG. 19D, at a step portion resulting from a difference in a thickness of the wiring film 504 and a thickness of the bank B, a step is also created in the insulation film 510. Since a thickness direction of the thin film increases in a stacking direction of the thin film shown by arrow Z in FIG. 19D, it will not grow in a direction perpendicular to the arrow Z. Consequently, a thin film part 511 where the insulation film 510 became thin was formed at the step portion. The following problems occurred resulting from these.
Problem 1
To prevent the wiring material from diffusing to the insulation film 510 covering the wiring film 504, the bank B, and the like, as shown in FIG. 19D, there is employed a method of providing a diffusion-preventing film 512 covering the wiring film 504. But, the residue 507 remaining on the bank B cannot be covered by the diffusion-preventing film 512, so that the wiring material may diffuse to the insulation film 510 and the like.
Problem 2
Likewise, the bulge 506 caused by the wiring film 504 as it bulged out onto the cornered portion of the bank B, cannot be covered by the diffusion-preventing film 512, hence, the wiring material may disffuse to the insulation film 510 and the like.
Problem 3
At the thin film part 511 where the insulation film 510 became thin at the step portion, insulating function of the insulation film 510 may not be sufficient at times. Consequently, as shown in FIG. 19E, when another wiring film 515 and a conductive layer of a semiconductor device are formed on the insulation film 510, there is an increased possibility of generating a defect such as a short-circuit between the wiring film 504 and the insulation film 515 and the conductor of the semiconductor device at the thin film part 511.
Problem 4
As shown in FIG. 19E, when there exists the bulge 506 caused by the wiring film 504 as it bulged out onto the cornered portion of the bank B, together with the thin film part 511 where the insulation film 510 became thin at the step portion, the bulge 506 and the thin film part 511 exist in mutual proximity in the vicinity of the step portion. This increases a possibility of generating a defect such as a short-circuit between the wiring film 504 and the wiring film 515 and the conductive layer of the semiconductor device through the bulge 506.
When the wiring material diffuses to the insulation film and the like, a change occurs in the function of the insulation film and the like, so that performance of the insulation film and the like as well as performance of the semiconductor device including the wiring film and the insulation film may deteriorate. Hence, that the wiring material diffuses to the insulation film and the like poses a serious problem.